diff --git a/adafruit_ble/__init__.py b/adafruit_ble/__init__.py
index 07bd8a5..37c205c 100755
--- a/adafruit_ble/__init__.py
+++ b/adafruit_ble/__init__.py
@@ -174,6 +174,8 @@ class BLERadio:
         :param float interval:  advertising interval, in seconds
         :param int timeout:  advertising timeout in seconds.
             If None, no timeout.
+
+        ``timeout`` is not available in CircuitPython 5.x and must be `None`.
         """
         advertisement_bytes = bytes(advertisement)
         scan_response_bytes = b""
@@ -183,13 +185,28 @@ class BLERadio:
             scan_response.tx_power = self.tx_power
         if scan_response:
             scan_response_bytes = bytes(scan_response)
-        self._adapter.start_advertising(
-            advertisement_bytes,
-            scan_response=scan_response_bytes,
-            connectable=advertisement.connectable,
-            interval=interval,
-            timeout=0 if timeout is None else timeout,
-        )
+
+        # Remove after 5.x is no longer supported.
+        if (
+            sys.implementation.name == "circuitpython"
+            and sys.implementation.version[0] <= 5
+        ):
+            if timeout is not None:
+                raise NotImplementedError("timeout not available for CircuitPython 5.x")
+            self._adapter.start_advertising(
+                advertisement_bytes,
+                scan_response=scan_response_bytes,
+                connectable=advertisement.connectable,
+                interval=interval,
+            )
+        else:
+            self._adapter.start_advertising(
+                advertisement_bytes,
+                scan_response=scan_response_bytes,
+                connectable=advertisement.connectable,
+                interval=interval,
+                timeout=0 if timeout is None else timeout,
+            )
 
     def stop_advertising(self):
         """Stops advertising."""
diff --git a/examples/ble_bluefruit_color_picker.py b/examples/ble_bluefruit_color_picker.py
index 2b197af..2bf3499 100755
--- a/examples/ble_bluefruit_color_picker.py
+++ b/examples/ble_bluefruit_color_picker.py
@@ -2,11 +2,13 @@
 
 import board
 import neopixel
+
+from adafruit_bluefruit_connect.packet import Packet
+from adafruit_bluefruit_connect.color_packet import ColorPacket
+
 from adafruit_ble import BLERadio
 from adafruit_ble.advertising.standard import ProvideServicesAdvertisement
 from adafruit_ble.services.nordic import UARTService
-from adafruit_bluefruit_connect.packet import Packet
-from adafruit_bluefruit_connect.color_packet import ColorPacket
 
 ble = BLERadio()
 uart_service = UARTService()
diff --git a/examples/ble_demo_central.py b/examples/ble_demo_central.py
index f492e66..433f3ad 100644
--- a/examples/ble_demo_central.py
+++ b/examples/ble_demo_central.py
@@ -10,13 +10,14 @@ import board
 import busio
 import digitalio
 import adafruit_lis3dh
-from adafruit_ble import BLERadio
-from adafruit_ble.advertising.standard import ProvideServicesAdvertisement
-from adafruit_ble.services.nordic import UARTService
 import neopixel
 
 from adafruit_bluefruit_connect.color_packet import ColorPacket
 
+from adafruit_ble import BLERadio
+from adafruit_ble.advertising.standard import ProvideServicesAdvertisement
+from adafruit_ble.services.nordic import UARTService
+
 
 def scale(value):
     """Scale an value from  (acceleration range) to 0-255 (RGB range)"""
diff --git a/examples/ble_demo_periph.py b/examples/ble_demo_periph.py
index ff6800c..5eb5ae5 100644
--- a/examples/ble_demo_periph.py
+++ b/examples/ble_demo_periph.py
@@ -6,14 +6,14 @@ and updates a Circuit Playground to show the history of the received packets.
 import board
 import neopixel
 
-from adafruit_ble import BLERadio
-from adafruit_ble.advertising.standard import ProvideServicesAdvertisement
-from adafruit_ble.services.nordic import UARTService
-
 # Only the packet classes that are imported will be known to Packet.
 from adafruit_bluefruit_connect.packet import Packet
 from adafruit_bluefruit_connect.color_packet import ColorPacket
 
+from adafruit_ble import BLERadio
+from adafruit_ble.advertising.standard import ProvideServicesAdvertisement
+from adafruit_ble.services.nordic import UARTService
+
 NUM_PIXELS = 10
 np = neopixel.NeoPixel(board.NEOPIXEL, NUM_PIXELS, brightness=0.1)
 next_pixel = 0
diff --git a/examples/ble_hid_periph.py b/examples/ble_hid_periph.py
index 8940bcc..f35fdd4 100644
--- a/examples/ble_hid_periph.py
+++ b/examples/ble_hid_periph.py
@@ -6,13 +6,15 @@ This example acts as a keyboard to peer devices.
 import sys
 import time
 
+from adafruit_hid.keyboard import Keyboard
+from adafruit_hid.keyboard_layout_us import KeyboardLayoutUS
+
 import adafruit_ble
 from adafruit_ble.advertising import Advertisement
 from adafruit_ble.advertising.standard import ProvideServicesAdvertisement
 from adafruit_ble.services.standard.hid import HIDService
 from adafruit_ble.services.standard.device_info import DeviceInfoService
-from adafruit_hid.keyboard import Keyboard
-from adafruit_hid.keyboard_layout_us import KeyboardLayoutUS
+
 
 # Use default HID descriptor
 hid = HIDService()